That is, one reason we keep having trading-related financial crises is that the people who engage in stock-trading are psychopaths, or even worse. Der Speigel has an article on a study done by the University of St. Gallen that showed traders are more reckless and manipulative than physcopaths. My favorite bit:

Particularly shocking for Noll [one of the researchers] was the fact that the bankers weren’t aiming for higher winnings than their comparison group. Instead they were more interested in achieving a competitive advantage. Instead of taking a sober and businesslike approach to reaching the highest profit, “it was most important to the traders to get more than their opponents,” Noll explained. “And they spent a lot of energy trying to damage their opponents.”

It’s just what happens when you put crazy people in the driver’s seat.